Common Insecticides Harm Honeybees, EPA Study Shows

Pesticides commonly used on cotton plants and citrus groves can be harmful to honeybees, according to a preliminary risk assessment released by the U.S. Environmental Protection Agency (EPA).

Based on field trials, researchers found imidacloprid - a common neonicotinoid insecticide that is chemically similar to nicotine - can cause drastic hive population declines in some of the world's most important pollinators.

"This is a pretty big step forward in increasing our understanding of the potential for imidacloprids to impact colony health," Jim Jones, the EPA's assistant administrator for chemical safety and pollution prevention, said in a statement.

The preliminary assessment - which has yet to be peer reviewed - revealed chemical residues of more than 25 parts per billion were found in the nectar and pollen of citrus and cotton crops, which honeybees carry back to their hives. Ultimately, this could impact how much honey bees produce. However, residues collected from corn plants and other leafy vegetables were below at-risk levels.

This is the first of four risk assessments conducted by the EPA on different classes of neonicontinoids, and the results will play a key role in how the U.S. government decides to control the use of pesticides.

The use of neonicotinoids, also known as neonics, has been a subject of heated debate because honeybees are crucial to our food supply. Nearly one-third of the human diet comes from insect-pollinated plants, and honeybees are responsible for 80 percent of that pollination.

"We have been saying for several years now that the EPA has enough information and data available to them to take strong action and to severely reduce the amount we are using these chemicals," Larissa Walker, who heads the pollinator programme at the Centre for Food Safety, added. "The new report supports the need for the EPA to really reduce and restrict the use of these chemicals."